Related Party Transactions

12 Months Ended

Dec. 31, 2017

Xcel Energy Services Inc. provides management, administrative and other services for the subsidiaries of Xcel Energy Inc., including SPS. The services are provided and billed to each subsidiary in accordance with service agreements executed by each subsidiary. SPS uses the service provided by Xcel Energy Services Inc. whenever possible. Costs are charged directly to the subsidiary and are allocated if they cannot be directly assigned.

Xcel Energy Inc., NSP-Minnesota, PSCo and SPS have established a utility money pool arrangement with the utility subsidiaries. See Note 4 for further discussion of this borrowing arrangement.

The table below contains significant affiliate transactions among the companies and related parties for the years ended Dec. 31:



(Thousands of Dollars)	2017		2016		2015
Operating revenues:
Electric	$	2	$	56	$	—
Operating expenses:
Purchased power	1,436		8,809		8,632
Other operating expenses — paid to Xcel Energy Services Inc.	196,558		188,175		197,134
Interest expense	—		189		156
Interest income	—		—		6

Accounts receivable and payable with affiliates at Dec. 31 were:



	2017				2016
(Thousands of Dollars)	Accounts Receivable		Accounts Payable		Accounts Receivable		Accounts Payable
NSP-Minnesota	$	964	$	—	$	935	$	—
NSP-Wisconsin	7		—		—		333
PSCo	—		279		—		745
Other subsidiaries of Xcel Energy Inc.	326		22,298		14		13,336
	$	1,297	$	22,577	$	949	$	14,414